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importane of computer

Computers are very important in every aspect of our lives. Computer usage is growing and bounds in business, industry, government, colleges, schools and other places. The offices where we work, the stores in which we shop, the schools we attend, the banks that handle our money, even the device we use in our homes are being radically altered by computers. Computers are now used in all aspects of education, both administration and teaching. Whether it is for school or home, work or play, computer can save your time and money, increase your productivity, and process information with speed and accuracy.

Classification of computer

Computers have come long way since the first operational computer in 1940s. Divisions among the types are increasing as technology improves. Let us classify the computers into two major categories as given below I. Based on the application of computers II. Based on the capacity and size of the microprocessor I. Classification - Application wise Based on the application of computers for various purpose the computers can be classified into three types (a) Analog computers (b) Digital computers (c) Hybrid computers a) Analog Computers Computers that use analog signals for calculating and transmitting data are called Analog computers. It can be defined as "A device that operates on data in the form of continuously varying physical quantities". The values of the analog signals are continuously changing with states in between high and low. Analog data is calculated using the concept of "measuring values" like magnitude in terms of voltage, length, current. The analog data is transmitted in a continuous form that closely resembles the information it represents. Electrical signals on a telephone line are nothing but analog data representing the original voice. SLIDE RULER is an example of analog computers. b) Digital Computers The computers that use digital signals to calculate and transmit data are called Digital Computers. The word digital is derived from the word "digit". The word digit simply means numeral. The digital signal has only two states in which it can be represented. They are ON and OFF or HIGH and LOW or 1 and 0. Digital data is calculated using the concept of "counting values". The result obtained from the digital computer is more accurate when compared to the analog computers. These computers manipulate digital data and perform arithmetic and logical operations. To facilitate the performance of digital computers intermediate languages such as BASIC, COBOL, FORTRAN, PASCAL, C, C++, JAVA etc., has been developed. Digital Computers are classified as: • General purpose computers A general-purpose computer is one that has the ability to store different programs of instructions Performs a variety of operations It is designed to do a wide variety of jobs rather than perform a specific activity. It is also called personal computers (PC's) • Special purpose computers Designed to perform one specific task Instructions is built into, or permanently stored in the machine Specialization results in the given task being performed very quickly and efficiently It is inflexible and cannot be easily used to perform other operations. Past, it was expensive. Now-a-days, for example, new cars have such devices installed to monitor and control fuel, ignition and other system. c) Hybrid Computers Computer systems that use both analog and digital mechanisms are called Hybrid Computers. Desirable features of analog and digital computers are combined to develop a hybrid computer. In a hospital, the intensive care unit, an analog device measures a patient's heart function, temperature and other vital signs, these measurements are then converted into numbers and supplied to a digital component that monitors the patient's vital signs and signals to a nurse's station.. Classification - Capacity and size of Microprocessor Computers are also classified into different types mainly based on processing and storage capacity. A Computer that is capable and used for general purpose business applications like billing, accounting, maintaining stock information ,....... cannot be used for very advanced applications like forecasting and analysis of weather phenomena, oil exploration, aircraft design etc. And those computers used for the latter purpose mentioned above are not necessary to be used for the former purpose, for the reason, they are highly advanced and very expensive. Hence, the computers can be classified as given below (a) Microcomputers (b) Minicomputers (c) Mainframe computers (d) Super computers a) Microcomputers - are the smallest category of computer and also called as Personal Computers (PCs). These computers that can either fit next to a desk (called the Desktop) or can be carried around (called the Laptop and Notebook). Microcomputers use microprocessor as its important device. Microprocessor is a chip used to perform arithmetic and logical operations. These computers can be used either as a stand alone machine or connected to a network. Microcomputers are used for general purpose business applications such as invoicing, accounting etc. b) Minicomputers are bigger in size, faster in speed, have more memory capacity and expensive when compared to the microcomputers. Minicomputers can be used for general purpose applications and as a server for small networks. These computers are relatively small but expensive computer with somewhat limited input and output capabilities. Minicomputers use large hard-disk units as online secondary storage. c) Mainframe computers are more powerful in processing, faster in speed, have large memory, and very expensive when compared to the micro and mini computers. The word mainframe refers to mean the "Central Processor". Their size varies depending on how many concurrent users they are serving - from a few hundreds to thousands when used in networks and has the capacity to support many powerful peripheral devices. Mainframe computers are used by multinational companies or by companies have many branches all over the country like banks, airlines, insurance, etc. d) Super computers are the largest, fastest, most expensive and very powerful computers available when compared to the types of computers discussed earlier. They occupy specially designed air-conditioned rooms and are often used for research and to process complex scientific applications like weather forecasting, oil exploration, aircraft design, mathematical research etc. Unlike microcomputers, which generally have only one CPU, super computers have hundreds of processors. CRAY-I is an example of super computer.

computer vs human being

Differences between Human Attitude and computer Attitudes Human Computer Can Think Cannot think by itself Gets Mental Tiredness Never gets Tiredness May do mistake Can't do mistake by itself Has limited speed Very High Speed Has limited Memory More Amount of memory Accuracy may be missing Never missing NB: "Ability of a Human to do anything a computer can do but a computer cannot do everything a human can do" is a true statement based on the following table

function of data processing

Functions of Data Processing Data Collecting Data Recording Sorting Classifying Calculating Storing and Retrieving Summarizing Communicating

Processing Methods

Information system uses two Processing Techniques 1. Batch Processing 2. Real Time Processing 1) Batch processing: Where data to be processed is accumulated over a period of time. The accumulated batch of transaction is processed periodically. Otherwise, gathers transactions and saves them for processing all at once. Very efficient but always delay in Processing. Online Processing [Also Online Real-Time Processing] Each transaction is processed as soon as it is received. There is no waiting to accumulate. Such as, a computerized Reservation system where an immediate responsible is useful. Otherwise, by contrast, Process transaction as they occur, Ex: Air Line reservation system Time Sharing Is the concurrent use of a single computer system by many users, each of which has an I/O device and can access the same computer at the same time. The computer gives each user a small, but frequently repeated, since of the time, so that each user gets almost immediate response. There fore, if a computer is shared by many unscheduled users simultaneously it is called TIME SHARING

data processing

Organization of data for the purpose of producing desired information; involves recording, classifying, sorting, summarizing, calculating, disseminating and storing data.

generation of computer

People have been processing data and information in some form since prehistoric times. However, it was the development of the computer that revolutionized information processing. The first large scale electronic computer the grand parent of today's hand held machines, was the Electronic Numerical Integrator and Computer/Calculator (ENIAC), which became operational in 1946. ENIAC contained approximately 18000 light bulb size electronic vacuum tubes, weighed 30 tons and occupied about 1500 square feet of floor space. From the start, computers have been developed through four so called generations or stages, each characterized by smaller size, more powerful and less expensive than its predecessor. FIRST GENERATION (1944 - 1958) Computers of this generation were manufactured using vacuum tubes. These computers were highly unreliable as the vacuum tubes failed very frequently. Punched cards were used for input and output. These computers were very huge in size, produced enormous amount of heat, very slow and very, very expensive. ENIAC and UNIVAC (Universal Automatic Computer) were the examples of first generation computer. ENIAC used 18,000 vacuum tubes for producing the results. SECOND GENERATION (1959 - 1963) By the early 1960s, transistors were developed and used in manufacturing computers. Transistor is an electronic switching device that alternatively allows or does not allow electronic signals to pass and it was comparatively smaller than vacuum tube. Transistors consumed less power and produced less heat when compared to the vacuum tubes. This second-generation computer tended to be smaller in size, more reliable, and considerably faster than first generation of computers. Magnetic cores and disk packs were introduced as storage devices. Programming languages like BASIC, FORTRAN, COBOL, etc. were used. THIRD GENERATION (1964 - 1970) During this period, the Integrated Chips very popularly known as ICs, started replacing the usage of individual transistors in manufacturing computers. Integrated Circuit is a complete circuit packed with hundreds of transistors and other electronic components on a small silicon chip. The size of the computers still got reduced with improved reliability and speed when compared to the previous generation of computers. The usage of RAM (Random Access Memory) and magnetic disks as the storage media became wide spread. FOURTH GENERATION (1971 - Now) Due to the technological development the Large Scale Integrated (LSI) and Very Large Scale Integrated (VLSI) circuits were developed which contained thousands to millions of transistors on a tiny chip. In 1971, Intel developed the microprocessor, which contained the entire CPU (the Control Unit, Memory Unit, and ALU) on a single chip, leading to the process of miniaturization - the development of smaller and smaller computers. As a result, the computers main memory capacity increased, the cost got decreased and speed also increased, which directly affected the types and usefulness of software that could be used. Software applications like Word Processing, Electronic Spreadsheets, Database Management Programs, Painting and Drawing programs, and so forth became commercially available giving more people reasons to use a computer. FIFTH GENERATION The fifth-generation computers are under development. These computers function with the Artificial Intelligence provided to it. Due to the artificial intelligence the computer will have the ability to learn by itself, can reason and make decision with the knowledge it possess.

History of Computers

The earliest mechanical computing device was the Abacus, named after the Chinese scientist Abacus, during 1200 A.D. 2. Later during 1614 a Scottish nobleman John Napier developed a tool called Napier's Bones as an aid for multiplication. 3. By 1642, the French philosopher and mathematician, Blaise Pascal developed a rotating wheel calculator, the predecessor of the later desk calculator. 4. During the period 1792 - 1871, a British mathematician and engineer, who is considered to be the Father of today's computer - Charles Babbage built a working model of a machine - the Difference Engine. Later the design of the Difference Engine was developed as Analytical Engine. 5. During 1880s, a statistician Herman Hollerith designed and developed Hollerith machine for processing the census data. The Hollerith machines used punched cards for data processing. 6. The first Electronic Calculator was developed by John Vincent Atanasoff in the late 1930s and along with Clifford Berry a prototype of the Atanasoff-Berry computer was constructed during 1939. 7. A fully electronic computer, the ENIAC (Electronic Numerical Integrator And Calculator) was built during 1943 to 1946 at the University of Pennsylvania. 8. In 1953, IBM announced a medium sized computer, IBM650. 9. In the Middle of 1960s, the Digital Equipment Corporation released its first PDP-1 computer.

definition of computer

the computer is a machine capable of doing several things without the intervention of a person Receiving and storing data and instructions Performing operations on the data as prescribed by the instructions Producing output in a form humans can understand